Substrate lift mechanism and reactor including same

ABSTRACT

A substrate support assembly suitable for use in a reactor including a common processing and substrate transfer region is disclosed. The substrate support assembly includes a susceptor and one or more lift pins that can be used to lower a substrate onto a surface of the susceptor and raise the substrate from the surface, to allow transfer of the substrate from the processing region, without raising or lowering the susceptor.

FIELD OF INVENTION

The disclosure generally relates to apparatus for gas-phase processes.More particularly, exemplary embodiments of the present disclosurerelate to a reactor including a common substrate transfer and processingregion and to a substrate lift mechanism suitable for use therein.

BACKGROUND OF THE DISCLOSURE

Gas-phase reactors for processing substrates, such as semiconductorwafers, often include a susceptor within a reaction chamber. Duringprocessing, one or more substrates are placed within the reactionchamber and onto the susceptor using a robotic arm. After processing,the substrate(s) are removed from the surface of the susceptor andthrough an opening in the reaction chamber using the robotic arm.

Often, it is desirable to maintain a relatively small reaction space orregion within the reaction chamber. The relatively small reaction spaceallows for more-efficient substrate processing. For example, a smalleramount of reactants can be used when processing substrates in arelatively small reaction space—compared to a larger reaction spaceand/or an amount of time to process substrates using the relativelysmall reaction space can be less than the amount of time to processsubstrates in the larger reaction space. To allow for a relatively smallreaction space within a reaction chamber, while allowing placement ofsubstrates onto the susceptor and removal of the substrates from thesusceptor, a reaction chamber often includes a separate wafer transferregion that includes the opening within the reaction chamber to allowplacement on and removal of the substrates from the susceptor.

During the substrate transfer process, lift pins, which extend through avertical width of the susceptor and beyond, are sometimes used tofacilitate placement and removal of the substrate on and from thesurface of the susceptor. In such cases, a substrate can be placed ontothe susceptor by placing (lowering) the susceptor to be within thesubstrate transfer region of the reaction chamber, causing the lift pinsto rise above the surface of the susceptor, placing the substrate ontothe lift pins, and lowering the lift pins, such that the substrate restson the susceptor. The susceptor and the substrate can then be moved(raised) to a processing position, such that the substrate is within thereaction region of the reaction chamber.

Although such techniques work relatively well to place substrates withinand remove substrates from a reaction space within the reactor,mechanisms to move the susceptor and the lift pins are relativelycomplex. In addition, reactors employing such techniques can exhibitundesired gas flow between the reaction region and the substratetransfer region—especially during substrate processing. The undesiredgas flow can lead to deposition and/or corrosion of the reactor withinthe substrate transfer region. Furthermore, the volumes of such reactorsare relatively large to accommodate both the processing/reaction regionand the substrate transfer region of the reaction chamber. In addition,the multi-step process of moving the susceptor to a transfer region andmoving the lift pins is a relatively time consuming. Accordingly,improved mechanisms and techniques for transferring and processingsubstrates are desired.

SUMMARY OF THE DISCLOSURE

Various embodiments of the present disclosure provide an improved methodand apparatus for processing and transferring substrates. As set forthin more detail below, various systems and methods provide a reactorand/or use a method that can process substrates within a region andtransfer substrates to/from the same region within a reactor. In otherwords, the reactor can include a reaction chamber including a commonprocessing and transfer region. Accordingly, the overall reactor volumecan be relatively small, the reactor can be less complex, more reliable,less expensive, and easier to maintain and/or process substrates in areduced amount of time and/or in a less expensive manner.

In accordance with at least one exemplary embodiment of the disclosure,a reactor, which includes a common substrate processing and transferregion, includes a reaction chamber comprising a reaction region, asusceptor having a top surface within the reaction region, and asubstrate lift mechanism. The substrate lift mechanism can include atleast one lift pin, a lift pin support member that engages to (e.g.,removably) couple to the at least one pin, and a movable shaft coupledto the lift pin support member. The substrate lift mechanism causes theat least one lift pin to extend above the susceptor surface. Inaccordance with various aspects of these embodiments, the moveable shaftmoves in a vertical direction. The distance that the movable shaft andthe lift pins move during a substrate transfer process can range fromabout 5 mm to about 25 mm, about 10 mm to about 20 mm, or be about 17mm. In accordance with further aspects of these embodiments, thesusceptor includes a center region and a peripheral region. A width ofthe center region can be greater than a width of the peripheral region.Such a design can facilitate forming the susceptor with a relativelysmall peripheral width, which in turn can facilitate use of the commonregion for both substrate processing and transfer. The reactor canfurther include a rotatable shaft and a susceptor support coupled to therotatable shaft. The susceptor is coupled to the susceptor support, suchthat rotational movement of the rotatable shaft is translated to thesusceptor. In accordance with various examples of these embodiments, anopening within the reaction chamber, to transfer substrates into and outof the reaction chamber, resides above a top surface of the susceptorwhen the susceptor is in a processing position.

In accordance with at least one other embodiment of the disclosure, asubstrate support assembly includes a susceptor, a susceptor supportcoupled to the susceptor, a rotatable shaft coupled to the susceptorsupport, a lift pin support member, one or more lift pins coupled to thelift pin support member, a moveable shaft coupled to the lift pinsupport member, a lift pin mechanism to cause the moveable shaft to movein a vertical direction, and a susceptor rotation mechanism that causesthe susceptor to rotate during substrate processing. The substratesupport assembly can be configured, such that the susceptor does notmove in a vertical direction during a substrate transfer process. Inaccordance with various aspects of these embodiments, the susceptorsupport includes a plurality of susceptor support arms and one or moresusceptor support structures coupled to each susceptor support arm. Thesusceptor arm(s) can include an aperture to receive one of the one ormore lift pins. The susceptor can be the same or similar to thesusceptor described above and elsewhere in this specification.

In accordance with at least one further exemplary embodiment of thedisclosure, a method of transferring and processing a substrate includesthe steps of providing a reactor comprising a common region forsubstrate processing and substrate transfer, providing a substratesupport assembly, such as the assembly described above and elsewhere inthis specification, providing a substrate to the common region, movingthe lift pins in a downward position to place the substrate in aprocessing position, processing the substrate, moving the lift pins inan upward position, and removing the substrate from the common region.The method can include removing the substrate from the common regionthrough an opening that is located above a top surface of thesusceptor—e.g., when the susceptor is in a processing position.

Both the foregoing summary and the following detailed description areexemplary and explanatory only and are not restrictive of the disclosureor the claimed invention.

BRIEF DESCRIPTION OF THE DRAWING FIGURES

A more complete understanding of the embodiments of the presentdisclosure may be derived by referring to the detailed description andclaims when considered in connection with the following illustrativefigures.

FIG. 1 illustrates a reactor in accordance with exemplary embodiments ofthe disclosure.

FIG. 2 illustrates components of a substrate support assembly inaccordance with additional embodiments of the disclosure.

FIGS. 3-5 illustrate a lift/rotate mechanism in accordance withexemplary embodiments of the disclosure.

It will be appreciated that elements in the figures are illustrated forsimplicity and clarity and have not necessarily been drawn to scale. Forexample, the dimensions of some of the elements in the figures may beexaggerated relative to other elements to help to improve understandingof illustrated embodiments of the present disclosure.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS OF THE INVENTION

The description of exemplary embodiments of methods and apparatusprovided below is merely exemplary and is intended for purposes ofillustration only; the following description is not intended to limitthe scope of the disclosure or the claims. Moreover, recitation ofmultiple embodiments having stated features is not intended to excludeother embodiments having additional features or other embodimentsincorporating different combinations of the stated features.

Any ranges indicated in this disclosure may include or exclude theendpoints. Additionally, any values of variables indicated (regardlessof whether they are indicated with “about” or not) may refer to precisevalues or approximate values and include equivalents, and may refer toaverage, median, representative, majority, or the like.

Turning now to FIG. 1, a reactor 100 in accordance with at least oneembodiment of the disclosure is illustrated. Reactor 100 includes areaction chamber 102 including a reaction region 104 and a substratelift mechanism 106. As described in more detail below, during asubstrate transfer operation, substrate lift mechanism 106 facilitatesplacement of a substrate 116 onto a top surface 122 of a susceptor 118within reaction region 104 to allow removal of substrate 116 through anopening 120 of reaction chamber 102.

Reaction chamber 102 can be formed of, for example, quartz, and can beformed as a unitary piece, such as a tube. By way of example, reactionregion 104 within reaction chamber 102 can have a rectangular crosssection having a width of about 350 mm to about 450 mm (or be about ˜420mm), a length of about 400 mm to about 800 mm (or be about ˜760 mm), anda height of about 20 mm to about 40 mm (or be about ˜30 mm). As notedabove, reaction chamber 102 includes an opening 120 that resides abovetop surface 122 of susceptor 118 (e.g., when surface 122 is in aprocessing position).

Reaction chamber 102 can be suitable for a variety of applications, suchas film (e.g., epitaxial) deposition processes, etch processes, cleaningprocessing, and the like. Further, reactor 100 can be a standalonereactor or form part of a cluster tool that may include similar ordifferent reaction chambers.

Substrate lift mechanism 106 includes at least one lift pin 108, 110, alift pin support member 112 that can engage with and couple to the atleast one pin 108, 110, and a movable shaft 114 mechanically coupled tothe lift pin support member. During a substrate transfer process,substrate lift mechanism 106 causes the at least one lift pin 108, 110to be raised or lowered to allow placement of substrate 116 onto surface122 and/or removal of substrate 116 from surface 122.

Lift pins 108, 110 can be formed of any suitable material. For example,lift pins 108, 110 can be formed of silicon carbide (SiC), SiC-coatedgraphite, quartz, or glassy carbon. Although two lift pins 108, 110 areshown in FIG. 1, reactor 100 includes three (e.g., equally) spaced apartlift pins. Reactors in accordance with other embodiments of thedisclosure can include any suitable number of lift pins and generallyinclude three or three or more lift pins. A length L of lift pins 108,110 can vary according to application. Generally a length of lift pins108, 110 allows lift pins 108, 110 to extend through a width W ofsusceptor 118 and above the susceptor top surface 122—for example, whenreceiving a substrate 116 from a robotic arm (not illustrated) orpresenting substrate 116 to be received by the robotic arm.

In accordance with some embodiments of the disclosure, lift pins 108,110 have a length L of about 20 to about 40 mm or about 30 mm. This is asignificantly shorter length than typical lift pins and allowsprocessing and substrate transfer within a common region, namelyreaction region 104. Lift pins 108, 110 can include a beveled section124 that is received within a portion of susceptor 118. Beveled section124 allows lift pins 108, 110 to be received within a via 126 withinsusceptor 118 and to be retained at a desired level (e.g., a top surfaceof lift pins can be about planar with surface 122 or reside just (e.g.,a few mm or less) below surface 122. This allows susceptor 118 to retainlift pins 108, 110 when, for example, lift pin support member 112 is notengaged with lift pins 108, 110. A top surface 128, 130 of lift pins108, 110 can have a diameter of about 3 to about 6 mm, or about 4 mm.Top surface 128, 130 can be polished to a smooth finish (e.g., aroughness average of about 0.05 to 0.2 μm or less) to prevent ormitigate surface damage to substrate 116 during a transfer process.

Lift pin support member 112 engages with lift pins 108, 110 and moveableshaft 114. In the illustrated example, lift pin support member 112removably engages with lift pins 108, 110 and is coupled to moveableshaft 114. This allows movable shaft 114 to move only in a verticaldirection (and not rotate), while allowing susceptor 118 to rotate—e.g.,during substrate processing, as described in more detail below. Lift pinsupport member 112 can be formed of, for example, SiC-coated graphite,quartz, or glassy carbon.

As illustrated in more detail in FIG. 2, lift pin support member 112includes a plurality of lift pin arms 202, 204. Although two lift pinsupport arms are illustrated in FIG. 2, the illustrated lift pin supportmember includes three lift pin support arms. Each lift pin support arm202, 204 includes a first end 206, 208 coupled moveable shaft 114 and asecond end 210, 212 that receive and engage with a lift pin (e.g., oneor lift pins 108, 110). Second end 210, 212 can include, for example, arecess 214, 216 to receive a bottom portion 218, 220 of one or lift pins108, 110. Lift pin support member 112 can be a unitary member, asillustrated. Alternatively, lift pin support member can include aplurality of arms coupled to a coupling that is coupled to moveableshaft 114.

FIG. 1 illustrates lift pins 108, 110 when engaged with lift pin supportmember 112, such that lift pin support member 112 engages with lift pins108, 110 and causes top surface 128, 130 of lift pins 108, 110 to resideabove surface 122. FIG. 2 illustrates lift pin support member 112, whenlift pin support member 112 is disengaged from lift pins 108, 110—i.e.,when moveable shaft 114 is moved in a downward position relative to theposition of moveable shaft 114 in FIG. 1. As illustrated in FIG. 2, whenlift pin support member 112 is disengaged from lift pins 108, 110, liftpins 108, 110 are retained by susceptor 118, allowing susceptor 118 torotate, without requiring support member 112 and/or moveable shaft 114to rotate.

Moveable shaft 114 is in the form of a hollow tube. Moveable shaft 114can be formed of, for example, quartz. In accordance with exemplaryembodiments of the disclosure, moveable shaft is configured to move avertical distance of 5 to about 25 mm (or ˜17 mm). As a result, liftpins 108, 110 can move about 5 to about 25 mm (or ˜17 mm), and lift pins108, can extend to a height of up to about 5, 10, or 20 mm above surface122.

Susceptor 118 can be formed of, for example, SiC or SiC-coated graphite.In accordance with various examples of the disclosure, width W ofsusceptor 118 is relatively small to allow lift pin-assisted substratetransfer and processing in a single region—e.g., reaction region 104. Inaccordance with various embodiments of the disclosure, a width W ofsusceptor 118 at a peripheral region 222 is less than a width ofsusceptor 118 at a center region 224 of susceptor 118. Thisconfiguration can allow from a relatively thin susceptor—especially atthe peripheral region—while allowing susceptor to rotate and performother functions, such as protecting an end of a thermocouple andproviding desired heat transfer to and/or from substrate 116. By way ofexamples, the width at peripheral region 222 ranges from about 3 toabout 6.5 mm (or ˜3.8 mm). A width of center region 224 can range fromabout 6 to about 10 mm (or ˜6.4 mm).

As noted above, reactor 100 can be configured to cause substrate 116 torotate during substrate processing. In this illustrated example, reactor100 includes a rotatable shaft 132 and a susceptor support 134 to causesusceptor 118, and consequently substrate 116, to rotate duringprocessing.

Rotatable shaft 132 can be formed of, for example, quartz. Rotatableshaft 132 can be configured to couple to susceptor support 134 totranslate rotational movement of rotatable shaft 132 to susceptorsupport 134. By way of example, rotatable shaft 132 can be coupled tosusceptor support 134 using a coupling 148.

As illustrated in FIGS. 1 and 2, susceptor support 134 includes one ormore (e.g., a plurality of) susceptor support arms 226, 228 andstructures 136, 138. Structures 136, 138 can engage with susceptor 118and susceptor support arms 226, 228. Alternatively, structures 136, 138can be integrally formed with susceptor support arms 226, 228. Susceptorsupport arms 226, 228 and structures 136, 138 can be formed of, forexample, SiC, SiC-coated graphite, or quartz. Although illustrated withone structure 136, 138 for each susceptor support arms 226, 228,susceptor support 134 can include a plurality of structures 136, 138 foreach susceptor support arm 226, 228. In accordance with exemplaryembodiments of the disclosure, at least one of the plurality ofsusceptor support arms 226, 228 includes an aperture 140, 142 to receivea lift pin.

Reactor 100 can also include a thermocouple 144. Thermocouple 144 can beused to measure a temperature of susceptor 118—for example—duringsubstrate processing. As illustrated in FIG. 1, thermocouple 144 caninclude an end 146, which extends through moveable shaft and rotatableshaft. End 146 can reside within center region 224 of susceptor 118.Center region 224 may provide additional radiation shielding for end 146of thermocouple 144.

In accordance with further exemplary embodiments of the disclosure, asubstrate support assembly 230 includes components to cause lift pins108, 110 to raise and lower and to cause susceptor 118 to rotate. Inaccordance with these embodiments, substrate support assembly 230includes susceptor 118, susceptor support 134, rotatable shaft 132, liftpin support member 112, one or more lift pins 108, 110, moveable shaft114, a lift pin mechanism to cause the moveable shaft to move in avertical direction during a substrate transfer process, and a susceptorrotation mechanism that causes susceptor 118 to rotate during substrateprocessing. As noted above, in accordance with various examples of thedisclosure, susceptor 118 does not move in a vertical direction duringsubstrate transfer—i.e., susceptor 118 does not move in a verticaldirection as lift pins are raised and/or lowered and/or during othersteps of a substrate transfer process. As described below, the lift pinmechanism and the susceptor rotation mechanism can be combined.

FIGS. 3-5 illustrate a lift/rotate mechanism 300 in accordance withexemplary embodiments of the disclosure. Lift/rotate mechanism 300 canbe used to raise and lower lift pins (e.g., lift pins 108, 110) and tocause a susceptor (e.g., susceptor 118) to rotate. FIG. 3 illustrates arear isometric view of lift/rotate mechanism 300, FIG. 4 illustrates afront isometric view of lift/rotate mechanism 300, and FIG. 5illustrates a simplified cross-sectional-view of lift/rotate mechanism300.

With reference to FIGS. 3 and 4, in the illustrated example, lift/rotatemechanism 300 includes a susceptor rotary actuator 302, a pin liftactuator 304, a rotary signal junction bracket, a tubulation seal 308, atubulation seal support 310, a susceptor manual actuator 312, athermocouple signal rotary junction 314, and a mounting bracket 316.

Susceptor rotary actuator 302 is used to provide rotational movement toa susceptor, such as susceptor 118. By way of example, susceptor rotaryactuator 302 is configured to provide rotational movement to rotatableshaft 132 to cause susceptor 118 to rotate—e.g., during processing of asubstrate—using rotational drive gear 512. Exemplary rotational speedcan range from about 5 rpm to about 150 rpm, about 10 rpm to about 50rpm, or be about 35 rpm.

Pin lift actuator 304 is configured to cause lift pins (e.g., lift pins108, 110) to move in a vertical direction. By way of example, pin liftactuator 304 causes a pin lift carriage 502 to move vertically along alinear slide rail 504. Carriage 502 is mechanically coupled to moveableshaft 114 (e.g., using a pin lift shaft mounting sleeve 506) to causelift pins (e.g., by way of lift pin support member 112) to move in avertical direction. Pin lift shaft mounting sleeve 506 and moveableshaft 114 can be protected from the environment using an upper bellows508 and a lower bellows 510.

Rotary signal junction box 306 can be used to facilitate provision ofsignals to and/or from susceptor rotary actuator 302, pin lift linearactuator 304, and/or one or more thermocouples, such as thermocouple144.

Tubulation seal 308 and a tubulation seal support 310 are used toprovide a seal about moveable shaft 114. As illustrated in FIG. 5,tubulation seal 308 can include a seal 514 and a support plate 516 toretain seal 514 as moveable shaft 114 moves relative to seal 308.

Although, in accordance with various embodiments of the disclosure, asusceptor does not move vertically during substrate processing, it maybe desirable to move a susceptor for maintenance, installation, or thelike. In such cases, susceptor manual actuator 312 can be used tomanually move a susceptor (e.g., susceptor 118) in a vertical directionvia a susceptor lift carriage 518.

In the illustrated example, lift/rotate mechanism 300 includes arelatively large feedthrough 520 (e.g., having a diameter of about 20 toabout 50 mm or be about 34.5 mm), which allows installation of moveableshaft 114, through a rotary feedthrough 522 and a susceptor shaftmounting sleeve 524, from below. A configuration of lift/rotatemechanism 300 is relatively compact, compared to lift/rotate mechanismthat cause a susceptor to move vertically during a substrate transferprocess.

In accordance with additional embodiments of the disclosure, a method oftransferring and processing a substrate is provided. The method canemploy the reactor, substrate support assembly, and/or lift/rotatemechanism as described herein. An exemplary method includes the steps ofproviding a reactor comprising a common region for substrate processingand substrate transfer, providing a substrate support assembly,providing a substrate to the common region, moving the lift pins in adownward position to place the substrate in a processing position,processing the substrate, moving the lift pins in an upward position,and removing the substrate from the common region. The step of removingthe substrate can include removing the substrate from the common regionthrough an opening in a reaction or processing region that is above atop surface of the susceptor.

Although exemplary embodiments of the present disclosure are set forthherein, it should be appreciated that the disclosure is not so limited.For example, although the apparatus and methods are described inconnection with various specific components, the disclosure is notnecessarily limited to these configurations. Various modifications,variations, and enhancements of the apparatus and methods set forthherein can be made without departing from the spirit and scope of thepresent disclosure.

What is claimed is:
 1. A reactor comprising a common substrateprocessing and transfer region, the reactor comprising: a reactionchamber comprising a reaction region; a susceptor having a top surfacewithin the reaction region; and a substrate lift mechanism comprising:at least one lift pin; a lift pin support member that removably engagesto the at least one pin; and a movable shaft coupled to the lift pinsupport member, wherein the substrate lift mechanism causes the at leastone lift pin to extend through a width of the susceptor and above thesurface.
 2. The reactor of claim 1, wherein the moveable shaft traversesa distance of about 5 mm to about 25 mm during a substrate transferprocess.
 3. The reactor of claim 1, wherein a length of the at least onelift pin ranges from about 20 mm to about 40 mm.
 4. The reactor of claim1, wherein the at least one lift pin comprises a top surface, andwherein the substrate lift mechanism causes the top surface to extendfrom below the top surface to a distance up to about 22 mm above the topsurface.
 5. The reactor of claim 1, wherein the susceptor comprises acenter region and a peripheral region and wherein a width of the centerregion is greater than a width of the peripheral region.
 6. The reactorof claim 5, wherein the width of the peripheral region ranges from about3 mm to about 6.5 mm.
 7. The reactor of claim 5, wherein the width ofthe center region ranges from about 6 mm to about 10 mm.
 8. The reactorof claim 5, wherein the reactor further comprises at least onethermocouple having an end, the thermocouple extending through themoveable shaft, and the end received within an opening in the centerregion.
 9. The reactor of claim 1, wherein the susceptor comprisesgraphite coated with silicon carbide.
 10. The reactor of claim 1,further comprising: a rotatable shaft; and a susceptor support coupledto the rotatable shaft, wherein the susceptor is coupled to thesusceptor support, such that a rotational movement of the rotatableshaft is translated to the susceptor.
 11. The reactor of claim 10,wherein the susceptor support comprises one or more susceptor supportarms and one or more susceptor support structures.
 12. The reactor ofclaim 11, wherein the one or more susceptor support structures couple tothe susceptor.
 13. The reactor of claim 11, wherein the one or moresusceptor support arms comprise an aperture to receive the at least onelift pin.
 14. A substrate support assembly comprising: a susceptor; asusceptor support coupled to the susceptor; a rotatable shaft coupled tothe susceptor support; a lift pin support member; one or more lift pinscoupled to the lift pin support member; a moveable shaft coupled to thelift pin support member; a lift pin mechanism to cause the moveableshaft to move in a vertical direction during a substrate transferprocess; and a susceptor rotation mechanism that causes the susceptor torotate during substrate processing, wherein the susceptor does not movein a vertical direction during substrate transfer.
 15. The substratesupport assembly of claim 14, wherein the susceptor support comprises aplurality of susceptor support arms and one or more susceptor supportstructures coupled to or integrated with each of the plurality ofsupport arms.
 16. The substrate support assembly of claim 14, wherein atleast one of the plurality of susceptor support arms comprises anaperture to receive a lift pin.
 17. The substrate support assembly ofclaim 14, wherein the susceptor comprises a center region and aperipheral region and wherein a width of the center region is greaterthan a width of the peripheral region.
 18. The substrate supportassembly of claim 17, further comprising at least one thermocouplehaving an end, the thermocouple extending through the moveable shaft,and the end received within an opening in the center region.
 19. Amethod of transferring and processing a substrate, the method comprisingthe steps of: providing a reactor comprising a common region forsubstrate processing and substrate transfer; providing the substratesupport assembly of claim 14; providing a substrate to the commonregion; moving the one or more lift pins in a downward position to placethe substrate in a processing position; processing the substrate; movingthe one or more lift pins in an upward position; and removing thesubstrate from the common region.
 20. The method of claim 19, whereinthe step of removing the substrate comprises removing the substrate fromthe common region through an opening above a top surface of thesusceptor in a processing position.